I had a cheap Sears router table and it was junk too. What size you need depends on what you will be routing. The longer and/or wider your pieces, the longer/wider your table needsto be. I am an advocate of putting the router to one side of the table. That way you can swing your fence around the bit fo narrow pieces or wide pieces.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.